High hardness, non-slip, large torque, long life and durable. The screwdriver head has strong magnetic so that it can self-lock the connecting rod. Strong practicability, it can change external six angle into internal six angle. It can join electric screwdriver, screwdriver, screwdriver nozzle, screwdriver head. It applicable for exchanging the sleeve and the joint, prolonging the connecting rod. It can be flexibly used in situation of narrow space, use it to reach the work-place where hands can not reach. Shank shape: Hex shank colour: silver Material: Carbon Steel + CRV size: Shank diameter: 1/4 inch (6.35mm) Sleeve diameter: 10mm Sleeve significant depth: 9.5mm Total length: 150mm Package Contents: 10x Drill Bit Extension Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.